| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus for reading a watermark image by disposing a light source to be inclined by only a predetermined angle with respect to a perpendicular face of an irradiation object, and by receiving scattered light generated by an effect that the light from the light source is scattered by undulation at a transmission portion of the irradiation object. <P>SOLUTION: The image reading apparatus includes: a conveyor means for conveying the irradiation object having a black watermark of a light transmission portion and a white watermark; a transmission type light source disposed at one face side of the irradiation object for irradiating the irradiation portion of the irradiation object with light inclined by only a predetermined angle with respect to the perpendicular face of the irradiation object; a rod lens array disposed in parallel with the perpendicular face of the irradiation object at the other face side of the irradiation object for converging the scattered transmitted light generated by an effect that the light irradiating the irradiation portion is scatter-reflected by the undulation of the black watermark and the white watermark of the irradiation object; a sensor for imaging the scattered transmitted light converged by the rod lens array, and outputting the imaged image at each line; and a signal processing unit for collating the image signal imaged by the sensor with black watermark image data of the irradiation object stored in advance. <P>COPYRIGHT: (C)2011,JPO&INPIT |
